at the most extreme (a) means that you are opening an issue in the name of the company. the question then is: were you allowed to do that? (many contracts forbid you to speak in the name if the company unless explicitly instructed)
and (b) would mean that you contributed a company resource to the project (namely you contributed yourself, your knowledge, etc), but it is the company who gets to say where you are allowed/supposed to contribute to
those would be the extreme interpretations, and in both cases, once it's done, it can't be taken back.
only code that you write can be taken back, so if you report a bug to me, i may not be able to use your solution to fix it, but your company can't stop me from knowing about the bug and then fixing it myself.
so (a) and (b) may be a contract violation and they may fire you for it, but that's all they can do. only (c) contains actual code that they can revoke if you didn't have the right to contribute it.
yes, true, but you can expand the code in (c) until it is big enough to matter. that's just a quantitative issue. (a) and (b) are qualitatively different. the report could be contain a few hundred lines of text and it still would be the same case.
at the most extreme (a) means that you are opening an issue in the name of the company. the question then is: were you allowed to do that? (many contracts forbid you to speak in the name if the company unless explicitly instructed)
and (b) would mean that you contributed a company resource to the project (namely you contributed yourself, your knowledge, etc), but it is the company who gets to say where you are allowed/supposed to contribute to
those would be the extreme interpretations, and in both cases, once it's done, it can't be taken back.
only code that you write can be taken back, so if you report a bug to me, i may not be able to use your solution to fix it, but your company can't stop me from knowing about the bug and then fixing it myself.
so (a) and (b) may be a contract violation and they may fire you for it, but that's all they can do. only (c) contains actual code that they can revoke if you didn't have the right to contribute it.